Method of detecting operating states of an electrical apparatus and electrical apparatus for detecting apparatus-specific operating states

ABSTRACT

A cordless mobile part and method that detects selection features for a number operating modes. The mobile part also controls functional sequences specific to the mobile part and identifies the operating modes specific to the mobile part, the operating modes include a first operating mode for operating on a convenience charging station; a second operating mode for operating on a standard charging station; a third operating mode for operating on a headset fourth operating mode for operating as a handset. A controller connected to the detection system is designed in such a manner that interrogation is performed at all the branch points in each decision level on the basis of a selection feature in accordance with a decision tree having a plurality of decision levels and level-immanent branch points.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for identifying various operatingmodes of an electrical apparatus specific to the telecommunicationfield.

2. Description of the Related Art

Electrical apparatuses which may assume different operating modes froman original mode include, for example, mobile telecommunicationequipment. Telecommunication equipment may be designed as cordlessmobile parts in accordance with the DECT/GAP Standard (Digital EuropeanCordless Telecommunication; see (1): Nachrichtentechnik Elektronik[Telecommunications Electronics] 42 (1992, January/February), No. 1,Berlin, DE; U. Pilger: “Struktur des DECT-Standards” [Structure of DECTStandard], pages 23 to 29; (2): Philips Telecommunication Review, Vol.49, No. 3, September 1991; R. Mulder: “DECT Universal Cordless AccessSystem”, pages 68 to 73;/Generic Access Profile; see ETSI-PublicationprETS 300444, April 1995, Final Draft, ETSI, FR) or as mobile radiomobile parts in accordance with the GSM Standard (Groupe Spéciale Mobileoder Global System for Mobile Communication; see Informatik Spektrum[Information Technology Spectrum] 14 (1991) June, No. 3, Berlin, DE; A.Mann: “Der GSM-Standard—Grundlage für digitale europäischeMobilfunknetze” [The GSM Standard—Basis of digital European mobile(radio networks], pages 137 to 152). The various operating modes of themobile telecommunication equipment are designed from standard featuresthat are specific to the telecommunications apparatus and/or fromperformance features which are specific to the telecommunicationsapparatus.

One standard feature that is specific to the telecommunication equipmentis the charging of the energy storage (for example a rechargeablebattery) used in the telecommunication equipment. One performancefeature that is specific to the telecommunication equipment is the“hands-free speech” and the “loudspeaker/hands-free listening”.

Reference EP-0 313 776 B1 discloses a mobile telecommunicationsapparatus (cordless mobile part) which, with a charging shell, forms a(temporary) functional unit in such a manner that both the “batteryrecharging” standard feature and the “hands-free speech” and/or“loudspeaker” performance feature can be activated.

Furthermore, Reference EP-0-624 021 A2 and WO 92/00640 disclose mobiletelecommunication equipment (cordless mobile parts and mobile radiohandsets) which can be used to achieve the performance feature“hands-free speech”. To this extent, the mobile telecommunicationequipment has an earpiece which is designed as an earphone or headsetand is connected (detachably) via a cord to the handset of thetelecommunication equipment. The other telecommunication-specific partsare arranged and/or contained in the handset. In order to achieve theperformance feature “hands-free speech”, it is possible—according toEP-0 624 021 A2—for the handset to be mounted with the microphoneand/or—according to WO 92/00640—an external microphone to be attached tothe earpiece cord in the vicinity of the mouth (for example a jacket orshirt pocket), and for the earpiece to be inserted into the ear.

On the basis of the configurations of a mobile telecommunicationequipment described above, a distinction is drawn between standardmobile parts and convenience mobile parts.

While standard mobile parts have only the standard feature “batteryrecharging”, both the standard feature “battery recharging” and theperformance feature “hands-free speech” and/or “loudspeaker/hands-freelistening” can be implemented in convenience mobile parts.

Examples of known circuit designs related to the invention are shown inFIGS. 1, 2 and 3 herein and further explained in an article published inComponents 31 (1993), Issue 6, pages 215 to 218; S. Althammer, D.Brückmann, entitled “Hoch-optimierte IC's für DECT-Schnurlostelefone”[Highly optimized ICs for DECT cordless telephones], (hereinafter“Components 31 Article”). FIG. 1 shows the basic circuit design of astandard mobile part S-MT which is used in the Siemens cordlesstelephone “Gigaset 951/952” (see telcom report 16 (1993), Issue 1, pages26 and 27) and forms a (temporary) functional unit with a standardcharging station S-LST for charging the energy storage (for example arechargeable battery) which is used in the standard mobile part S-MT.

In FIG. 1, the circuit design consists of a first radio part S-FKTconnected to a first signal processing device S-SVE. The first signalprocessing device includes a first signal control part S-SST designed asa burst mode controller S-BMC, and a first signal conversion part S-SUTdesigned as a CODEC and AD/DA converter. A first clock generator S-TG isconnected to a first microcontroller S-μC designed as a centralcontroller S-ZS. A first BOF interface S-BSS for a first operatorinterface S-BOF. The operator interface consists of a first keypad S-TA,a first display device S-AE, a first earpiece S-HK, a first microphoneS-MF and a first bell S-TRK. A first power supply S-SV is connected to afirst connection interface S-ASS for the standard charging stationS-LST. The method of operation of the circuit design in FIG. 1 isfurther described in the Components 31 Article cited above.

Based on reference EP-0 313 776 B1 and on the above referencedComponents 31 Article, FIG. 2 shows the principle of the circuit designof a convenience mobile part K-MT, which forms a (temporary) functionalunit with a convenience charging station K-LST for charging the energystorage (for example a rechargeable battery) which is used in theconvenience mobile part S-MT, and for providing the performance feature“hands-free speech” and “loudspeaker”.

In FIG. 2, the circuit design incorporates a second radio part K-FKT anda second signal processing device K-SVE. The signal processing deviceK-SVE includes a second signal control part K-SST designed as a burstmode controller K-BMC and a second signal conversion part K-SUT designedas a CODEC and AD/DA converter. A second clock generator K-TG isconnected to a second microcontroller K-μC designed as a centralcontroller K-ZS. The microcontroller K-μC also includes ananalog/digital converter ADW. A second BOF interface K-BSS for a secondoperator interface K-BOF having a second keypad K-TA connected to theBOF interface. The second operator interface also has a second displaydevice K-AE connected to an output of the BOF interface. The secondoperator interface K-BOF also has a second earpiece K-HK and a secondbell K-TRK, each connected to an output of the BOF interface. A secondmicrophone K-MF of the operator interface K-BOF is connected to a inputof the BOF interface. A second power supply K-SV is connected to asecond connection interface K-ASS for the convenience charging stationK-LST. The principle of the method of operation of the circuit design isdescribed in the Components 31 Article cited above.

As further described in references EP-0 624 021 A2 and WO 92/00640 andin conjunction with the Components 31 Article, FIG. 3 shows theprinciple of the circuit design of the convenience mobile part K-MTaccording to FIG. 2 and further provides the performance feature“hands-free speech” and “hands-free listening”. In FIG. 3, theconnection interface K-ASS is connected, preferably detachably, to aheadset KSG with a headset microphone KSMF and a headset earpiece KHK.

The circuit design in FIG. 3 shows the radio part K-FKT, the signalprocessing device K-SVE with the signal control part K-SST designed as aburst mode controller K-BMC, and the signal conversion part K-SUTdesigned as a CODEC and AD/DA converter, the clock generator K-TG, themicrocontroller K-μC designed as a central controller K-ZS and having ananalog/digital converter ADW, the BOF interface K-BSS for the operatorinterface K-BOF having the keypad K-TA, the display device K-AE, theearpiece K-HK, the microphone K-MF and the bell K-TRK, the power supplyK-SV and the connection interface K-ASS for the headset KSG areconnected in a similar manner as described in FIG. 2 above. An exampleof the method of operation of the circuit design is described in theComponents 31 Article cited above.

There are thus four possible operating modes for the convenience mobilepart K-MT: (1) hands-free speech/loudspeaker operation in conjunctionwith the convenience charging station K-LST and operation on theconvenience charging station K-LST (first operating mode); (2) operationon the standard charging station S-LST (second operating mode); (3)hands-free speech/hands-free listening operation with the headset KSG(third operating mode); and (4) normal/conventional handset operation(fourth operating mode).

SUMMARY OF THE INVENTION

In accordance with the teachings of the present invention, an object ofthe invention is for an electrical apparatus to identify a number ofdifferent operating modes of the electrical apparatus quickly, easilyand reliably.

This object is achieved on the basis of a method for identifyingoperating modes of an electrical apparatus having an original mode inwhich the electrical apparatus establishes a first number “n” equal tothe number of operating modes where “n is greater or equal to 4” fromthe original mode, interrogation is performed at all the branch pointsto determine the selection feature of the corresponding operating modesin accordance with a decision tree. The decision tree includes a numberof decision levels and level-immanent branch points, interrogation isperformed at all the branch points, in each decision level, on the basisof the same selection feature; and this object is also achieved in anelectrical apparatus that has an original mode and assumes a number “n”of a number of operating modes where n≧4 from the original mode, theapparatus includes a means for detecting selection features for theplurality of operating modes; and means for controllingapparatus-specific functional sequences wherein the functional sequencesare designed in such a manner that interrogation is performed at alllevel-immanent branch points in each of a number of decision levels of adecision tree on the basis of a selection feature.

In an embodiment, a number “n” of electrical apparatus operating states,where “n≧4”, the electrical apparatus is able to identify theapparatus-specific operating modes by interrogating on the basis of aselection feature at all the branch points in a decision level of adecision tree having a plurality of decision levels and level-immanentbranch points.

In an alternative embodiment, cordless mobile part that detects theselection features of the operating modes and controls the functionalsequences which are specific to the mobile part, identifies theoperating modes which are specific to the mobile part quickly, easilyand reliably. A first operating mode entitled “Operation on aconvenience charging station”, a second operating mode entitled“Operation on a standard charging station”, a third operating modeentitled “Operation on a headset” and a fourth operating mode entitled“Operation as a handset” are connected to the detection means and aredesigned in such a manner that interrogation is in each case carried outon the basis of the same selection feature at all the branch points ineach decision level, in accordance with the decision tree having thedecision levels and the level-immanent branch points.

In another embodiment, the cordless mobile part results in a high degreeof compatibility between the convenience mobile parts, standard mobileparts, standard charging stations and convenience charging stations.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the detailed description of thepresently preferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a circuit diagram of a standard mobile telecommunicationssystem.

FIG. 2 shows a circuit diagram of a convenience mobiletelecommunications system.

FIG. 3 shows a circuit diagram of a convenience mobiletelecommunications system.

FIG. 4 shows a circuit diagram for the operation of a convenience mobilepart on a convenience charging station (first operating mode),

FIG. 5 shows a circuit diagram for the operation of a convenience mobilepart on a standard charging station (second operating mode),

FIG. 6 shows a circuit diagram for the operation of a convenience mobilepart on a headset (third operating mode),

FIG. 7 shows a circuit diagram for the operation of a standard mobilepart on a convenience charging station (fifth operating mode),

FIG. 8 shows a flow chart for assuming four possible operating modes(first to fourth operating modes) of the convenience mobile part from anoriginal mode “Call with mobile part for example by pressing the ‘call’key”,

FIG. 9 shows a flow chart for various changes in the operating mode ofthe convenience mobile part.

FIG. 10 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 11 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 12 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 13 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 14 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 15 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 16 shows a flow chart for an alternative embodiment of aconvenience mobile telecommunication system.

FIG. 4 shows a first operating mode BZ1 of the convenience mobile partK-MT according to FIG. 2, in which the second connection interface K-ASSof the convenience mobile part K-MT is connected to the conveniencecharging station K-LST according to FIG. 2. The first operating mode BZ1is characterized by two partial operating modes, which represent thestandard feature “battery recharging” and the performance feature“hands-free speech and loudspeaker”, a first partial operating mode“battery recharging” and a second partial operating mode “hands-freespeech and loudspeaker”.

The connection between the convenience mobile part K-MT and theconvenience charging station K-LST for these partial operating modes isproduced via

a) four connecting contacts of the second connection interface K-ASS ofthe convenience mobile part K-MT according to FIG. 2 (convenienceconnecting contacts), a first convenience connecting contact K-AK1, asecond convenience connecting contact K-AK2, a third convenienceconnecting contact K-AK3 and a fourth convenience connecting contactK-AK4, and

b) four charging station contacts of the convenience charging stationK-LST according to FIG. 2 (convenience charging station contacts), afirst convenience charging station contact K-LK1, a second conveniencecharging station contact K-LK2, a third convenience charging stationcontact K-LK3 and a fourth convenience charging station contact K-LK4.

The convenience mobile part K-MT is charged from the conveniencecharging station K-LST via the charging station contacts K-LK1, K-LK2and the connecting contacts K-AK1, K-AK2.

Signaling information items which activate the performance feature“hands-free speech” and “loudspeaker” are exchanged between theconvenience charging station K-LST and the convenience mobile part K-MTvia the charging station contacts K-LK1, K-LK2, K-LK3 and the connectingcontacts K-AK1, K-AK2, K-AK3.

Analog voice signals are transmitted bidirectionally in the course ofthe activated performance feature “hands-free speech” and “loudspeaker”via the charging station contacts K-LK3, K-LK4.

In order to avoid control errors on the convenience mobile part K-MT inthe partial operating modes of the first operating mode BZ1, thetransmission

a) of the charging current from the convenience charging station K-LSTto the convenience mobile part K-MT,

b) of the signaling information items from the convenience chargingstation K-LST to the convenience mobile part K-MT and from theconvenience mobile part K-MT to the convenience charging station K-LST,and

c) of the analog voice signals from the convenience charging stationK-LST to the convenience mobile part K-MT and from the conveniencemobile part K-MT to the convenience charging station K-LST must becontrolled. This is done in the convenience mobile part K-MT by thecentral controller K-ZS, K-μC in conjunction with two switching elementsSE1 SE2. The first switching element SE1 is designed as a chargingswitch. The second switching element SE2 is designed as anacknowledgement switch. When the convenience mobile part K-MT is in theoriginal mode both switching elements SE1, SE2 are closed. This originalmode of the convenience mobile part K-MT also applies to FIG. 5 and FIG.6 described below.

Standard Feature “Battery Recharging” (first partial operating mode)

In order to recharge the rechargeable battery K-SV according to FIG. 2,the convenience charging station K-LST has a plug connection K-SA thatis connected to an AC power supply (for example 220 V AC). An input of amain voltage transformer K-NST is connected to the plug connection K-SA.An output of the main voltage transformer K-NST is connected to a thirdswitching element SE3. The third switching element SE3 is designed as aseries regulator. These components are connected to the first chargingstation contact K-LK1 and produce a charging current LS. The chargingcurrent LS flows through a bridge rectifier BGR in the connectioninterface K-ASS of the convenience mobile part K-MT. After this, thecharging current LS passes via the closed charging switch SE1 to therechargeable battery K-SV. A closed charging circuit is produced by thecommon ground connection between the convenience mobile part K-MT andthe convenience charging station K-LST via the second connecting contactK-AK2 and the second charging station contact K-LK2.

Performance Feature “Hands-free Speech” and “Loudspeaker” (secondpartial operating mode)

The implementation,of the performance; feature “hands-free, speech” and“loudspeaker” is composed of two phases: (1) a preparation phase; and(2) an activation phase.

During the preparation phase, a first signaling information item SI1 inthe form of a first signaling current is transmitted via the firstcharging station contact K-LK1 and the connecting contact K-AK1 to theconvenience mobile part K-MT. The signaling information item SI1 isinitiated in the convenience charging station K-LST by manual operationof a momentary-contact switch TA and is produced by a pulse generator PGwhich is connected to the series regulator SE3. In order to transmit thesignaling information item SI1, the pulse generator PG brieflyinterrupts the transmission path for the charging current LS and at thesame time connects the transmission path for the signaling informationitem SI1 to the charging station contact K-LK1. The signalinginformation item SI1 which is transmitted to the convenience mobile partK-MT is detected in an identification circuit EKS which has aswitch-mode regulator (not shown), and is passed on to the centralcontroller K-ZS. The closed circuit for the first signaling current isachieved by the common ground connection between the convenience mobilepart K-MT and the convenience charging station K-LST via the secondconnecting contact K-AK2 and the second charging station contact K-LK2.

In an activation phase, which follows the preparation phase, the centralcontroller K-ZS ensures that the charging switch SE1 is opened, and thatthe acknowledgement switch SE2 is closed at the same time. By closingthe acknowledgement switch SE2, a second signaling information item SI2is fed via the third connecting contact K-AK3 and a third chargingstation contact K-LK3 to a hands-free speech/loudspeaker circuit FLS inthe convenience charging station K-LST. The second signaling informationitem SI2 is used as an acknowledgement information item for the firstsignaling information item SI1 and is in the form of a second signalingcurrent. On receiving this signaling information item SI2, thehands-free speech/loudspeaker circuit FLS switches on a hands-freespeech microphone FMF and a loudspeaker LSP.

After this, the central controller K-ZS checks via the analog/digitalconverter ADW whether any microphone current MFS is flowing as aconsequence of the hands-free speech microphone FMF having been switchedon.

If the microphone current MFS is flowing, then

a) the microphone K-MF and the earpiece K-HK in the convenience mobilepart K-MT are switched off by the central controller K-ZS, K-μC and

b) the acknowledgement switch SE2 remains closed.

Otherwise,

a) the microphone K-MF and the earpiece K-HK in the convenience mobilepart K-MT remain switched on and

b) the acknowledgement switch SE2 is opened.

If the microphone current MFS is flowing, then the performance feature“hands-free speech” and “loudspeaker” is activated, and the analog voicesignals can be transmitted bidirectionally between the hands-free speechmicrophone FMF and the BOF interface K-BSS according to FIG. 2, as wellas the BOF interface K-BSS and the loudspeaker LSP via the chargingstation contacts K-LK3, K-LK4 and the connecting contacts K-AK3, K-AK4.

The closed circuit for the second signaling current, the microphonecurrent MFS and the analog voice signals is once again achieved by thecommon ground connection between the convenience mobile part K-MT andthe convenience charging station K-LST via the second connecting contactK-AK2 and the second charging station contact K-LK2.

The performance feature “hands-free speech” and “loudspeaker” ispreferably activated in the manner described above by the conveniencemobile part K-MT via the acknowledgement switch SE2 and the centralcontroller K-ZS, K-μC. To this extent, the preferred deactivation occursby the convenience mobile part K-MT via the acknowledgement switch SE2and the central controller K-ZS, K-μC. Upon deactivation of theperformance feature, the charging switch SE1 is preferably reset—for asubsequent charging process—again to its closed original position. Theactivation and deactivation of the performance feature by theconvenience mobile part K-MT has the advantage that there is no risk ofthe hands-free speech/loudspeaker circuit FSL being activatedinadvertently in the event of any bounce of the mobile part occurringwhen said mobile part is inserted into the convenience charging stationK-LST, which is designed as a charging shell.

The above statements, which relate to a convenience mobile part K-MThaving the performance feature “hands-free speech” and “loudspeaker”,can also be extended to convenience mobile parts K-MT having theperformance feature “hands-free speech” and/or “loudspeaker”, takingaccount of the performance-feature-specific changes linked to this.

FIG. 5 shows a second operating mode BZ2 of the convenience mobile partK-MT according to FIG. 2, in which the second connection interface K-ASSof the convenience mobile part K-MT is connected to the standardcharging station S-LST according to FIG. 1. In the second operating modeBZ2, only the standard feature is supported, with the second connectioninterface K-ASS according to FIG. 4, by the convenience mobile part K-MTwhich is designed for the standard feature “battery recharging” and theperformance feature “hands-free speech” and “loudspeaker”.

The connection between the convenience mobile part K-MT and the standardcharging station S-LST is in this case produced via

a) the first connecting contact K-AK1 and the fourth connecting contactK-AK4 of the four convenience connecting contacts of the secondconnection interface K-ASS of the convenience mobile part K-MT accordingto FIG. 4, and

b) two charging station contacts of the standard charging station S-LSTaccording to FIG. 1 (standard charging station contacts), a firststandard charging contact S-LK1 and a second standard charging stationcontact S-LK2.

The second connecting contact K-AK2 and the third connecting contactK-AK3 remain unused for the connection between the convenience mobilepart K-MT and the standard charging station S-LST. This means that thefirst switching element SE1, which is designed as a charging switch, ispermanently closed in the second operating mode BZ2, and the secondswitching element SE1, which is designed as an acknowledgement switch,is permanently closed in the second operating mode BZ2—thus, in theoriginal mode.

a) connecting contact K-AK3 and the fourth connecting contact K-AK4 ofthe four convenience connecting contacts of the second connectioninterface K-ASS of the convenience mobile part K-MT according to-FIG. 4,and

b) three headset contacts of the headset KSG according to FIG. 3, afirst headset contact KK1, a second headset contact KK2 and a thirdheadset contact KK3.

The first connecting contact K-AK1 remains unused for the connectionbetween the convenience mobile part K-MT and the headset KSG. This meansthat the first switching element SE1, which is designed as a chargingswitch, is permanently closed in the third operating mode BZ3 (originalmode of the switching element SE1).

Since the acknowledgement switch SE2 is closed in the original state,when the headset contacts KK1 . . . KK3 of the headset KSG are pluggedonto the connection interface K-ASS by means of the connecting contactsK-AK2 . . . K-AK4, the headset KSG is automatically activated, togetherwith the headset microphone KSMF and the earpiece/headset loudspeakerKHK/KLSP.

A check is now carried out once again via the analog/digital converterADW in the central controller K-ZS to determine whether any microphonecurrent MFS is flowing as a result of the headset microphone KSMF havingbeen switched on.

If this is the case, then

a) the microphone K-MF and the earpiece K-HK in the convenience mobilepart K-MT are switched off by the central controller K-ZS, K-μC and

b) the acknowledgement switch SE2 remains closed.

Otherwise,

a) the microphone K-MF and the earpiece K-HK in the convenience mobilepart K-MT remain switched on and

b) the acknowledgement switch SE2 remains closed.

If any microphone current MFS is flowing, then the performance feature“hands-free speech” and “hands-free listening” is activated, and theanalog voice signals can be transmitted bidirectionally between theheadset microphone KSMF and the BOF interface K-BSS according to FIG. 3,as well as the BOF interface K-BSS and the earpiece KHK, via the headsetcontacts KK2, KK3 and the connecting contacts K-AK3, K-AK4.

The closed circuit for any microphone current MFS and for the analogvoice signals is achieved by the common ground connection between theconvenience mobile part K-MT and the headset KSG via the secondconnecting contact K-AK2 and the first headset contact KK1.

The above description, which relate to a convenience mobile part K-MThaving the performance feature “hands-free speech” and “hands-freelistening” can also be extended to convenience mobile parts K-MT havingthe performance feature “hands-free speech” and/or “hands-freelistening”, taking into account the performance-feature-specificchanges.

A further, fourth operating mode BZ4 of the convenience mobile part K-MTaccording to FIG. 2 and FIG. 3 is handset operation, in which theconvenience mobile part K-MT is operated without a convenience chargingstation K-LST, without a standard charging station S-LST and without aheadset KSG. The connecting contacts K-AK1 . . . K-AK4 all remain unusedin this case.

FIG. 7 shows a fifth operating mode BZ5 of the standard mobile part S-MTaccording to FIG. 1, in which the first connection interface S-ASS ofthe standard mobile part S-MT is connected to the convenience chargingstation K-LST according to FIG. 2. In the fifth operating mode BZ2, onlythe standard feature is supported, with the first connection interfaceS-ASS according to FIG. 1, by the standard mobile part S-MT which isdesigned for the standard feature “battery recharging”, although theconvenience charging station K-LST has the capability for “hands-freespeech” and “loudspeaker”.

The connection between the standard mobile part S-MT and the conveniencecharging station K-LST is in this case produced via

a) the first charging station contact K-LK1 and the fourth chargingstation contact K-LK4 of the four charging station contacts of theconvenience charging station K-LST according to FIG. 2, and

b) two connecting contacts of the standard mobile part S-MT according toFIG. 1 (standard connecting contacts), a first standard connectingcontact S-AK1 and a second standard connecting contact S-AK2.

The second charging station contact K-LK2 and the third charging stationcontact K-LK3 remain unused for the connection between the standardmobile part S-MT and the convenience charging station K-LST. This meansthat the hands-free speech/loudspeaker circuit FLS is inactive.

In order to recharge the rechargeable battery S-SV in the standardmobile part S-MT according to FIG. 1, the charging current LS isproduced in the convenience charging station K-LST by the plugconnection K-SA for the AC power supply (for example 220 V AC) and thepower supply voltage transformer S-NST. In the first connectioninterface S-ASS of the standard mobile part S-MT, the charging currentLS first of all flows through the bridge rectifier BGR, which isconnected to the first connecting contact S-AK1. After this, thecharging current LS passes via the closed charging switch SE1 to therechargeable battery S-SV. A closed charging circuit is produced by thecommon ground connection between the standard mobile part S-MT and theconvenience charging station K-LST, via the second connecting contactS-AK2 and the fourth charging station contact K-LK4. To this end, thebridge rectifier BGR is connected in the illustrated manner by a firstoutput to the ground potential of the connection interface S-ASS and ofthe standard mobile part S-MT, and by a second output via the secondconnecting contact S-AK2, the fourth charging station contact S-LK4 anda diode D, to the ground potential of the convenience charging stationK-LST.

FIG. 8 shows a flow chart illustrating how the convenience mobile partK-MT assumes the four operating modes BZ1 . . . BZ4 from an originalmode AZ (“Call with the mobile part, for example by pressing the ‘call’key”), which is implemented and runs in the central controller K-ZS ofthe convenience mobile part K-MT. The flow chart comprises a decisiontree ESB having two decision levels, a first decision level ESE1 and asecond decision level ESE2. In the first decision level ESE1, there is afirst branch point VZS1, at which interrogation is carried out on thebasis of a first selection feature SM1 (“is any charging currentflowing?”) for the operating modes BZ1 . . . BZ4.

In the second decision level ESE2, there are two second branch pointsVZS2, at which interrogation is in each case carried out on the basis ofa second selection feature SM2 (“is any microphone current flowing?”)for the operating modes BZ1 . . . BZ4.

FIG. 9 to FIG. 16 show flow charts for various changes in the operatingmode of the convenience mobile part K-MT, which are implemented and runin the central controller K-ZS.

Although other modifications and changes may be suggested by thoseskilled in the art, it is the intention of the inventors to embodywithin the patent warranted hereon all changes and modifications asreasonably and properly come within the scope of their contribution tothe art.

I claim:
 1. A method for identifying a plurality of operating modes ofan electrical apparatus, the method comprising the steps of:establishing an original mode; assuming a first number “n” of theplurality of operating modes where “n≧4” from the original mode;defining a decision tree having a plurality of decision levels and aplurality of level immanent branch points, wherein for n operatingmodes, there are a second number “m” decision levels such that“2^(m)≧n≧2^(m−1)+1”; and performing an interrogation, in sequentialfashion from a first decision level to a last decision level of theplurality of decision levels; at each of the branch points on each ofthe plurality of decision levels on the basis of a same selectionfeature of the plurality of operating modes in accordance with thedecision tree, wherein each respective result of the interrogation atthe branch points on the last decision level directly results in theidentification of a respective one of the plurality of operating modes.2. The method as claimed in claim 1, further comprising the step of:operating the electrical apparatus in a first operating mode foroperating on a convenience charging station, a second operating mode foroperating on a standard charging station, a third operating mode foroperating on a headset or a fourth operating mode for operating as ahandset.
 3. The method as claimed in claim 1, wherein the step ofperforming an interrogation further comprises the steps of: detecting afirst selection feature for the flow of charging current; and detectinga second selection feature for the flow of microphone current.
 4. Anelectrical apparatus having an original mode and assuming a number “n”of a plurality of operating modes wherein “n≧4” from the original mode,the apparatus comprising: means for detecting selection features for theplurality of operating modes; and means for controllingapparatus-specific functional sequences connected to the means fordetecting selection features, where the apparatus-specific functionalsequences are designed in such a manner that an interrogation isperformed, in sequential fashion from a first decision level to a lastdecision level of a plurality of decision levels, at all level-immanentbranch points on each of the plurality of decision levels of a decisiontree on the basis of a same selection feature wherein for n operatingmodes, there are a second number “m” decision levels such that“2^(m)≧n≧2^(m−1)+1”, wherein each respective result of the interrogationat the branch points on the last decision level directly results in theidentification of the respective one of the plurality of operatingmodes.
 5. The electrical apparatus as claimed in claim 4, wherein theelectrical apparatus is a cordless mobile part.
 6. The electricalapparatus as claimed in claim 5, wherein the cordless mobile part has afirst operating mode for operating on a convenience charging station, asecond operating mode for operating on a standard charging station, athird operating mode for operating on a headset and a fourth operatingmode for operating as a handset.
 7. The electrical apparatus as claimedin claim 6, wherein the means for detecting detects the flow of chargingcurrent and the flow of microphone current.
 8. The electrical apparatusas claimed in claim 6 further comprising: four connecting contacts inthe means for detecting by which the electrical apparatus (K-MT) can beconnected to a convenience charging station, a standard charging stationor a headset.